Linux 5.8 Adding NTB Support For Upcoming Ice Lake Xeon CPUs

Normally the NTB patches for new kernel cycles aren't particularly noteworthy but this time around for Linux 5.8 is Icelake support.

The non-transparent bridge (NTB) support is for connecting separate memory systems of multiple computers to the same PCI Express fabric. With Linux 5.8, Intel NTB support with PCIe Gen4 is added for Ice Lake Xeon CPUs.

The NTB Linux code handles the point-to-point communication and other matters between the systems for handling point-to-point PCI Express bus connections. With the Icelake Gen4 NTB support, most of the code builds upon Intel's prior generations of NTB support, namely Skylake. Adding in the Ice Lake support is just over 600 lines of new code to Intel's NTB driver.

The Ice Lake support is the only main addition for the NTB changes of Linux 5.8, but the rest of the fixes and other maintenance items are outlined via this pull request.

Ice Lake 10nm+ Xeon CPUs are launching this year as the Cascade Lake successor (and the more limited scope Cooper Lake) with PCI Express 4.0 capabilities and other big improvements thanks to Sunny Cove cores.